1. Field of the Invention
This invention relates to a method and apparatus for generating an image file in which data for a stereographic display is recorded and a method and apparatus for controlling an image display when a stereographic synthetic image is to be displayed.
2. Description of the Related Art
In the field of computer vision, the position of a point, which is visually recognized when a photography space is seen from a certain direction, is optically measured, whereby a three-dimensional shape of an object disposed in the photography space is recognized or the depth of the photography space is recognized. As a method of measurement, there have been known a stereo image method where the principle of trigonometry is used, a TOF (time of flight) method where a time from the projection of light to receipt of the reflected light is measured, and a light section method where pattern light is investigated when slit light is projected.
An image, in which the position of the visually recognizable point is represented by coordinates of a predetermined coordinate system and the values of the coordinates are recorded as pixel values, is generally called a “distance image” or a “depth image”. Such a distance image includes information on a spatial position recognized by humans due to the fact that humans see objects with both eyes. On the other hand, the RGB data or a gradation image obtained by normal photography includes information on color and/or brightness recognized by a human when he or she sees an object. Accordingly, by combination of information obtained from the distance image and information obtained from the RGB data or the like, information substantially equivalent to that obtained by vision of a human when he or she sees the object can be recognized by a computer. Further, this makes it feasible to form and display an image which is viewed as a stereographic by the human. For example, in U.S. Patent Application Publication No. 20020030675, an apparatus or a system for a stereographic image display is disclosed.
In the image processing of two-dimensional images, synthesis of a plurality of images into an image of a new composition is often carried out. In the case of stereographic images as well, there are many needs where a plurality of pieces of data for a stereographic display obtained through a plurality of cameras (or through a camera at different times) are synthesized into an image of a new composition. Further, in display control of a two-dimensional image, enlargement of a specified region of interest is often carried out. There are needs also in the stereographic display to carry out the same display control.
However, since the image processing of a three-dimensional image is more complicated and requires longer time as compared with a two-dimensional image, the displaying speed is lowered when the synthesis or the enlargement is carried out immediately before.